Body Pressures

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

Body Pressures

Common  body pressure measurements include blood pressure  (80/120-mm (300 mm Hg, max)), respiratory pressure (4 kPa) and intraocular pressure for glaucoma testing (15 mm Hg). However, there are several other pressure measurements made at different body locations, most are made for diagnostic purposes. These include:

  • intra-bladder pressure (IBP) 12.3 ± 4.5 mmHg depending on body position to about 22 mmHg.
  • intragastric pressure, (IGP) 15.5 ± 3.5 mmHg vs 18.0 ± 8.7 mmHg
  • intra-abdominal pressure (IAP) typically less than 12 mmHg
  • anorectal manometry (ARM) 49 ± 3 mmHg resting to 238 ± 38 mmHg maximum squeeze range
  • vacuum (negative pressure) for an electric breast pump 0-270 mmHg

Similar to blood pressure and intraocular pressure, higher than normal readings identify potentially dangerous health situations. For example, an IAP equal to or above 12 mmHg is called Intra-abdominal Hypertension (IAH). Also, an IAP above 20 mmHg with evidence of organ dysfunction/failure defines abdominal compartment syndrome (ACS). Both of these higher than normal readings are known to cause significant morbidity and mortality among critically ill patients.

For healthy subjects, anal pressure is highly reproducible on separate days. ARM measurements in resting mode vary from 49 ± 3 to 58 ± 3 mmHg in women and from 49 ± 3 to 66 ± 6 mmHg in men. In contrast, maximum pressures range from 90 ± 9 to 159 ± 45 mm Hg in women and from 218 ± 18 to 238 ± 38 in men.

Oral to anal pressures vary depending on the location of the muscle cross sectional area (MCSA).

Oral to anal pressures vary depending on the location of the muscle cross sectional area (MCSA).
Source:  Physiology of the Gastrointestinal Tract .

Depending on the location, a significantly lower pressure can be a problem, too. For most people, blood pressure in the foot is similar to the blood pressure in the arm. A pressure drop of as little as 10% can indicate peripheral artery disease (PAD).

Not all pressures are positive measurements or made for diagnostic purposes. For example, an electric breast pump uses a vacuum (negative pressure) as high as 270 mmHg to collect milk for newborns.

For all of these body pressure measurements, highly accurate microelectromechanical systems (MEMS) pressure sensors can provide an essential tool for optimum healthcare.

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